Hydraulic booster apparatus



May 14, 1968 A. z. BAUER 3,382,669

HYDRAULIC BOOSTER APPARATUS Filed May 25, 1966 2 Sheets-Sheet l E SM EMay 14, 1968 A. z. BAUER 3,382,669 HYDRAULIC BOOSTER APPARATUS Filed May25, 1966 2 Sheets-Sheet 2 /Qg U ik y .1"

11 PRESS u RE SEL ECTOR VALVE 1NVENT0R. ,9L/wos Z. Baus ATTORNEY UnitedStates Patent O 3,382,669 HYDRAULIC BOSTER APPARATUS Alajos Z. Bauer,Norwalk, Conn., assigner to Burndy Corporation, a corporation of NewYork Filed May 25, 1966, Ser. No. 552,743 4 Claims. (Cl. oil-10.5)

ABSTRACT F THE DISCLOSURE A hydraulic apparatus, for operating devicessuch as portable crimping tools, which is designed independently of afluid pressure source and reservoir so that it may be attachedconveniently to an external source and reservoir such as are found incommon use on aerial lift trucks. The apparatus includes a hydraulicbooster pump which is adapted to be driven by the fluid pressure derivedfrom the external source, and control valve means together with apressure reducing valve which will permit selective operation of thebooster pump so as to supply either reduced pressure or boosted pressureto the utilization device.

This invention relates to a hydraulic booster aparatus, and moreparticularly to an apparatus which can be connected to an existinghydraulic system to generate and control sufficient pressure foroperating various devices, such as an electrical connector crimpingtool.

It is well known that hydraulic compression tools of the type used insecuring electrical connectors to power lines commonly require pressureto be supplied at two different values on an alternate, selective basis.That is, a first pressure of 100 p.s.i. might be used to gently grip aconnector between the jaws of the tool during an initial positioningoperation, and a second pressure of 10,000 p.s.i. might be used for fullcompression force.

The reservoirs, pumps, compressors, and motive power sources for systemsof this type are generally impractical to carry from one job to another.Further, their cost makes it desirable to avoid duplication whereverpossible. Since compression tools of the type described are often usedon or in the near vicinity of hydraulically operated aerial lift or boomtrucks, it has been conceived that the hydraulic system normally carriedby such trucks might be provided with a tap for supplying pressure to ahydraulic tool. However, the fluid pressure available from lift trucksmay typically be on the order of 1500 p.s.i. which is just between thetwo alternate Values required for compression tool operation.

Accordingly, it is an object of this invention to provide a hydraulicsystem capable of operating on an input fluid supply pressure of anintermediate value so as to selectively produce output pressures whichare substantially higher and substantially lower that the input,respectively.

It is a further object of the present invention to provide a hydraulicbooster apparatus which can be directly connected to the existinghydraulic system of an aerial bucket truck.

Further objects of this invention are, to provide a system than can beadjusted to provide a range of different maximum pressures, that can beoperated by hand on sight or by remote control, and that is relativelysmall in size and weight so as to make it easily portable.

These and other objects, features, and advantages of this invention willbe illustrated and made more apparent by the system which is describedin the following specification, particularly pointed out in the appendedclaims, and illustrated in the accompanying drawings, in which FIGURE 1is a diagrammatic layout of a hydraulic ICC booster system assembled inaccordance with this invention;

FIGURE 2 is a schematic representation of the control value of thesystem of FIGURE l, shown in the HOLD position; y

FIGUR-E 3 represents the control of FIGURE 2 in the OFF position;

FIGURE 4 is a schematic representation of the output and control valveportions of the system of FIGURE 1 showing modiiications thereof; and

FIGURE 5 is a pictorial representation of how a system of the type heredisclosed might be carried on a commercial boom and bucket Referring nowto FIGURE 1 of the drawings, the hydraulic booster system of thisinvention may be seen to comprise generally the operating elements 10(enclosed within the dotted envelope) which are provided with a fluidinput line 12, an output line 14, and a reservoir return line 16. Theoperating elements 10 include as basic equipment, a control valve 20 anda pumping unit 10; associated with the pumping unit are a shuttle valve50, a pressure relief valve 60, a check valve 70, and a pressurereducing valve 80.

In practice, input line 12 would be connected to the high pressurehydraulic line (not shown) of an available hydraulic system in, forexample, a hydraulically operated lift or boom truck. Reservoir returnline 16 would in turn be connected to the fluid storage reservoir ofsuch an available system in order to provide a complete flow path forthe overall system of the invention. Commercially available iluidcoupling devices of the quickdisconnect type might preferably be usedfor establishing these connections.

In use, output line 14 would be coupled to a hydraulic crimping tool orother such device for utilizing the uid pressure output of thisinvention.

Operation of the system illustrated in FIGURE 1 may be brielly describedas follows: Overall operation is manually controlled by the position ofcontrol lever 21 on control valve 20. Three positions are provided,namely OFF, HOLD and CRIMP. In the OFF position shown in FIGURE 3, theilow of liuid from input line 12 is completely cut off at valve 20, andthe pressure in all other lines of the system is allowed to drain to thereservoir pressure in return line 16. In the HOLD position shown inFIGURE 2, lluid at 1500 psi. from line 12, is applied to pressurereducing valve 80. ri`his valve reduces the 1500 p.s.i. to a value of100 psi, and transmits the reduced pressure iiuid through check valveinto the output portion 42 of pumping unit 40 and then into output line14. The CRIMP position of valve 20 shown in FIG- URE 1, applies 1500p.s.i. pressure from line 12 through line 23 directly to shuttle valve50'. This starts and operates the pump portion 45 of pumping unit 40.Operation of pump portion 46 raises or boosts the fluid pressure inoutput portion 42 of the pumping unit 40, from 100 p.s.i. toapproximately 10,000 p.s.i. and forces this high pressure fluid intooutput line 14. Manipulation of valve 20 thus permits the pressure inoutput line 14 to be varied selectively from reservoir pressure top.s.i. and to 1500 p.s.i.

A detailed explanation of fluid flow in this system during crimpingoperation may best be understood by reference to FIGURE 1. In the CRIMPposition of valve 2t), input port P1 is internally coupled to both ofoutput ports P2 and P3, and exhaust port P4 is effectively sealed. Fluidfrom line 12, at 1500 p.s.i. pressure, is thus applied to rcducingvalve30, through line 22 which extends from port P2, and to shuttle valve 50,through line 23 which extends from port P3.

assassa Shuttle valve 50` is a two-way, two-position iluid valve whichis provided with an inlet line 23, two outlet lines 51 and 52, and anexhaust line 53. It operates in a wellknown manner to connect one outletline to the inlet line and the other outlet line to the exhaust line,and to alternately reverse these connections in response to the positionof shuttle arm d. The position of shuttle arm 54 is controlled byextension rod 47 which is coupled at one end to arm 54 and at the otherend to pump plunger 49. Rod 47 and plunger 49' are in turn positioned byiluid forces acting on pump piston 48 which is mounted to rod 47. Forexample, with arm 54 in the position shown in FIGURE 1, iiuid from line23 at 1500 p.s.i. pressure will be directed through outlet line 51 andbe applied against the left side of piston 48, thereby forcing thepiston toward the right, together with rod 47 and plunger 4?. Outletline 52 at this time will be internally coupled, through shuttle valve5d, to exhaust line 53, so that liuid on the right of piston 48 mayreturn to the system reservoir through lines 52, 53 and 16. As piston 48reaches the extreme right end of its stroke, it will also have movedshuttle arm 54 to the right, thereby reversing the internal connectionsof lines 51 and 52 'within valve Si); In the new position of valve 50,1500 p.s.i. pressure will be applied to the right face of piston 43,forcing it toward the left. In this manner, piston 4S and plunger 49will continue to reciprocate left and right, as long as uid pressurefrom line 12 is applied to line 23 through control valve 20.

The reciprocating operation described above drives plunger 49alternately into and out of compression charnber 43 within outputportion 4Z of pumping unit 46. Chamber 43 is kept continuously illedwith hydraulic fluid supplied through check valve 70 and check valvefeed line 72. As plunger d?! enters chamber 43, it tends to compress thefluid which is trapped within the chamber by the one-way dowcharacteristics of check -valve 70. When the pressure of the entrappedfluid becomes high enough, it acts to unseat valve head 44 against theload imposed by valve spring 4S, and permits the lluid to flow throughpassages 41 in valve head 44 into valve cylinder 38 and then into outputline 14. The characteristics of plunger 49, chamber 43 and valve loadingspring 45 may thus he chosen to produce a desired hydraulic pressure(such as 10,000 p.s.i.), in the uid which passes through valve cylinder38 into output line 14.

FIGURE 2 illustrates duid low and internal connections for control valve2d in the HGLD position. In this position, ports P4 and P3 are closed,and input port P1 is internally connected to port P2. With port 173closed there is no iluid flow in line 23, so that shuttle valve 5d andpumping unit d@ will not operate. However, 1500 p.s.i. iluid from line12 will be supplied to pressure reducing valve 30 through ports P1 andP2 and line 22. Accordingly, 100 p.s.i. luid will pass from the pressurereducing valve E50 to check valve 7d and then to compression char ber 43in output portion 42 of pumping unit 4d. Valve head 44 will then unseatunder the 100 p.s.i. pressure, and by-pass passages 41 in valve head t4will permit the 100 p.s.i. duid in chamber 43 to dow into line 14.

In the OFF position of control valve 2d, schematically illustrated inFIGURE 3, input port P1 is closed to shut off iiuid flow through line12, and ports P2 and P3 are internally connected to exhaust port P4. Asmay be seen more readily from FIGURE 1, the internal connectionsestablished by the OFF position of valve 2li permit the fluid in lines14, 22 and 23 to return to the reservoir pressure level of lines 16 and16'. In the OFF condition of the system, pressure in output line 1li isdrained olf to line 16 through operation of pressure relief valve 60. Asshown in FIGURE 1, pressure relier valve 6@ include a spring loadedsafety valve portion and a spring-andpiston operated drain valve portion62. The input iluid sides of portions and 62 are cach coupled to valvecylinder 38 in pumping unit 4t) by a common passage 63. The output tluidsides of both of these portions are coupled by a common passage 64directly to exhaust branch line 16. Safety valve portion 61 operates inconventional manner to exhaust fluid from passage 63 into exhaust branch16 whenever the pressure in cylinder 38 exceeds a predetermined maximumvalue. Operation of drain valve portion 62 on the other hand, iscontrolled by duid pressure applied to valve piston 65. Drain valveportion 62 may be moved left or right to respectively open or obstructconnecting passage 67 which couples passage 63 to passage 64.-. A branch2?.' of line 22 subjects the left face of drain valve piston 65 to theduid pressure which exists in line 22. When this system is in eitherCRIMP or HOLD position, the pressure in line 22 is sufficient to movepiston 65 and valve portion `62 to the right so as to seal passage 6'7against fluid ilow. In OFF condition, however, the tluid pressure inline 22 and branch line Z2 is essentially the same exhaust value as inexhaust lines 16 and 16', and accordingly there is no fluid pressureforce acting on the left face of piston 65. Elimination of duid pressureon piston 65 permits the force of drain valve spring 66 to `move valveportion 62 toward the left, thereby opening connecting passage 67, andpermitting high pressure uid in line 14 and chamber 38 to exhaust to thelower pressure of line 16' through passages 63, 67 and 64. The pressurein output line 14 is thus reduced to its inital value so that anotherOFF-HOLD-CRIMP cycle of operation may be begun.

FIGURE 4 illustrates modications and additions which may be embodiedinto the system of FIGURE 1 within the scope of this invention. Elementsshown in this ligure which have corresponding counterparts in FIGURE lare denoted by identical reference numerals increased by 160. Thus, forexample, control valve 120 in FIGURE 4 corresponds generally to controlvalve 20 in FIGURE l. In the embodiment illustrated in FIGURE 4, thecontrol lever on control valve 120 has been replaced by a pneumaticactuator 118. This actuator may comprise any well known form ofpneumatically powered drive mechanism capable of producing at leastintermittent arcuate motion to rotate the shaft of valve 120. Amechanism of this type could be activated 'by a hand-held squeeze-bulbsuch as 119 which might be coupled to actuator 118 by a liexiblepneumatic tube 117 of convenient length. Such an actuator assembly wouldpermit an operator to control a system of the type described accuratelyand conveniently, using non-conductive, non-electrical means, from aremote location.

-T he embodiment of FIGURE 4 further illustrates means for permittingthe selection of either one of two different maximum output pressures ina system of the type disclosed. To do this, a pressure selector valve isposi- -tioned in the system interposed between pump output line 114 andnal output lines 114e and 1141). In use, the selector valve would beprovided with input pressure from line 114 at a maximum value of, say10,000 p.s.i. Depending on the position of selector lever 113i, theinput pressure may be passed directly through to line 114a with noreduction in value, or may be internally routed through a reducingportion (not detailed) within valve 115, before passing to line 11427 ata reduced value of, for example, 6,000 psi. A connection to exhaust linebranch 116 through sub branch 116 is provided to allow for any overflowor backup conditions within the valve. It can now be seen that acommercially available selector valve of this type, incorporated intothe system of FIGURE l would substantially enhance the versatility andllexibility of such a system.

It can also be seen that such a system, incorporating availablecomponents, might be included within a case 9i) of reasonable size suchas is shown in FIGURE 5. Such a case might be provided with one of moreseparabie hydraulic connectors 92 so that it could be convenientlycarried into and mounted to a platform or bucket 94 on the aerial boomarm 9'1 of a lift truck (not shown).

'Ihis invention has now been described, but it should be understood thatit is not confined to the particular forms or uses shown and described,the same being merely illustrative, and that the invention may becarried out in other ways without departing from the spirit of myinvention, and therefore, the right is broadly claimed to employ allequivalent instrumentalities coming within the scope of the appendedclaims, and by means of which, objects o'f our invention are attainedand new results accomplished, as it is obvious that the particularembodiments herein shown and described are only some of the many thatcan be employed to attain these objects and accomplish these results.

I claim:

1. A hydraulic booster apparatus for attachment to a separately existinghydraulic fluid system which has a pressurized hydraulic outlet port,said apparatus compn'sing:

first fluid conduit means, forming a hydraulic fluid passage which isattacha'ble at a second end thereof to a hydraulic fluid utilizationdevice;

a hydraulic fluid pumping-unit forming part of said conduit meansbetween the said first and second ends of said fluid passage;

said hydraulic fluid pumping-unit having an inlet directed toward thesaid first end of said fluid passage and an outlet directed toward thesaid second end of said fluid passage and being operable selectively toincrease the pressure of fluid in said fluid passage from a givenpressure at the inlet to a greater pressure at the outlet;

a fluid-driven motive power source operatively coupled to said pumpingunit to permit selective operation of said pumping unit;

a fluid flow control valve interposed in said first conduit meansbetween the said first end of said fluid passage and the saidpumping-unit;

second fluid conduit means forming a hydraulicfluid passage between saidfluid flow control valve and said fluid-driven motive power source forsupplying fluid to drive said motive power source;

said control Valve being operable to selectively block and permit fluidthrough said first conduit means to the said second end thereof, and tosimultaneously block and permit fluid flow through said second conduitmeans to said fluid-driven motive power source for causing selectiveoperation of said pumping-unit;

whereby said apparatus may be made to deliver fluid from said separatelyexisting hydraulic fluid system to said utilization device selectively,with or without increased pressure, in response to the operation of saidfluid flow control valve.

2. -A hydraulic booster apparatus in accordance with claim 1, furtherincluding a pressure-reducing valve means interposed in said firstconduit means between the said first end thereof and the said pumpingunit, for reducing the pressure of the fluid obtained from saidseparately existing hydraulic system from an initial pressure to a lowerpressure before said fluid is supplied to the said inlet of saidpumping-unit.

3. A hydraulic booster apparatus in accordance with claim 2 wherein saidseparately existing hydraulic fluid system includes a fluid storagereservoir which is provided with an inlet port for receiving returnfluid, and said booster apparatus further includes:

a one-Way check-valve interposed in said first conduit means betweensaid pressure reducing valve means and said pumping unit, for limitingfluid flow to the direction from said reducing valve means to saidpumping-unit only;

auxiliary conduit means coupled at a first end thereof to the inlet partof said separately existing hydraulic fluid system and coupled at asecond end thereof to said first conduit means between said one-waycheckvalve and the said second end of said first conduit means forreturning fluid to said fluid storage reservoir;

and, pressure-operated relief-valve means interposed in said auxiliaryconduit means between the said first and second ends of said auxiliaryconduit means, for controlling the return of fluid from said pumpingunit to the said fluid storage reservoir.

4. A hydraulic booster apparatus, for attachment to a separatelyexisting hydraulic fluid system which has a pressurized hydraulic fluidoutlet port and a fluid storage reservoir with an inlet port forreceiving returned fluid, said apparatus comprising:

first fluid conduit means, forming a hydraulic fluid passage which isattachable at a first end thereof to the pressurized hydraulic fluidoutlet port of a hydraulic fluid system and is attachable at a secondend thereof to a hydraulic fluid utilization device;

a hydraulic fluid pumping-unit forming part of said conduit meansbetween the said rst and second ends of said fluid passage;

said hydraulic fluid pumping-unit having an inlet directed toward thesaid first end of said fluid passage and an outlet directed toward thesaid second end of said fluid passage and 'being operable selectively toincrease the pressure of fluid in said fluid passage from a givenpressure at the inlet to a greater pressure at the outlet;

a fluid-driven reciprocating motive power source including a shuttleValve means, operatively coupled to said pumping-unit to permitselective operation of said pumping-unit and adapted to be driven byhydraulic fluid pressure obtained from said hydraulic fluid systemthrough said first conduit means;

a fluid-flow control Valve, having first, second and third operatingpositions, interposed in said first conduit means between the said firstend of said fluid passage and the said pumping-uit;

an inlet on said fluid flow control valve forming part of said firstconduit means;

a first outlet on said fluid flow control Valve, forming part of saidfirst conduit means;

a second outlet on said fluid flow control valve operatively coupled tosaid reciprocating motive power source for supplying operating fluidpressure thereto;

pressure-reducing valve means interposed in said first conduit meansbetween the said rst end thereof and the said pumping-unit, for reducingthe pressure of the fluid obtained from said separately existinghydraulic system from an initial pressure to a lower pressure beforesaid fluid is supplied to the said inlet of said pumping-unit;

a one-way check-valve interposed in said first conduit means lbetweensaid control valve means and said pumpingeunit for limiting uid flow tothe direction from said control valve means towards said pumpingunitonly;

auxiliary conduit means having a first end thereof coupled to theinletport of said separately existing hydraulic fluid system and asecond end thereof coupled to said first conduit means fbetween saidone-way check-valve and the said second end of said first conduit meansfor returning fluid to the said fluid storage reservoir;

a pressure operated relief valve means interposed in said auxiliaryconduit means between the said first and second ends of said auxiliaryconduit means for selectively controlling the return of fluid from saidfirst conduit means to the said fluid storage reservoir;

fluid passage means operatively coupling said pressure-operated reliefvalve means to said first conduit means intermediate said fluid flowcontrol valve means and said one-way check-valve for supplying uidpressure to operate said relief valve in response to the position ofsaid fluid ow control valve means;

a third outlet on said fluid ow control valve means operatively coupledto said inlet of said lluid storage reservoir for returning hydraulicfluid from said control valve means to said fluid storage reservoir inresponse to the position of said fluid low control valve means;

the said first position of said lluid low control valve means `beingadapted to -block iluid flow from the rst end of said first conduitmeans and to provide fluid flow passage means coupling said irst andsecond outlets to said third outlet for returning uid from saidapparatus to said fluid storage reservoir;

the said second position of said fluid flow control valve means beingadapted to block fluid ow from said second and third outlets and toprovide fluid tlow passage means coupling said inlet to said outlet forpermitting iluid ow from said rst end to said second end of said conduitmeans; and

the said third position of said uid flow control valve means beingadapted to block fluid ow through said third outlet and to provide uidow passage means coupling said inlet to said rst and second outlets forpermitting fluid llow through said first conduit means and for supplyingfluid pressure to operate said reciprocating motive power source.

References Cited UNITED STATES PATENTS 886,379 5/1908 Laursen 103-501,332,340 3/1920 Horne 60-51 1,888,990 ll/ 1932 Kurath 60-54.5 2,080,6955/1937 Garg-ile 103-50 2,608,059 8/1952 Kux 60-54.5 2,867,088 1/1959 Kux60-545 3,041,975 7/ 1962 Atherton et al 103-50 3,186,173 6/1965 Hogg60-54.5

FOREIGN PATENTS 768,258 2/ 1957 Great Britain.

20 MARTIN P. SCHWADRON, Primm Examiner.

R. R. BUNEVICH, Assistant Examiner.

